An organic electronic device means a device that requires exchanging of electric charges between electrodes using holes and/or electrons and organic materials. The organic electronic device may be largely divided into the following two categories according to an operation principle. First, there is an electronic device in which an exiton is formed in an organic material layer by a photon that flows from an external light source to the device, the exiton is separated into electrons and holes, and the electrons and the holes are respectively transferred to different electrodes and used as a current source (voltage source). Second, there is an electronic device in which holes and/or electrons are injected into an organic material semiconductor forming an interface with the electrode by applying a voltage or a current to two or more electrodes, and the device is operated by the injected electrons and holes.
Examples of the organic electronic device include an organic light emitting device, an organic solar cell, an organic photoconductor (OPC), an organic transistor and the like, and all of the devices require a hole injection or transporting material, an electron injection or transporting material, or a light emitting material in order to drive the device. Hereinafter, an organic light emitting device will be mainly described in detail, but in the organic electronic devices, the hole injection or transporting material, the electron injection or transporting material or the light emitting material are operated on the basis of a similar principle.
In general, an organic light emitting phenomenon refers to a phenomenon that converts electric energy into light energy by using an organic material. The organic light emitting device using the organic light emitting phenomenon has a structure which typically includes an anode, a cathode, and an organic material layer that is disposed therebetween. Herein, the organic material layer frequently has a multilayered structure that includes different materials in order to enhance efficiency and stability of the organic light emitting device, and may include, for example, a hole injection layer, a hole transporting layer, a light emitting layer, an electron transporting layer, an electron injection layer and the like. In the structure of the organic light emitting device, if a voltage is applied between two electrodes, holes are injected from an anode and electrons are injected from a cathode into the organic material layer, and when the injected holes and electrons meet each other, an exciton is formed, and light is emitted when the exciton falls to a bottom state. It is known that this organic light emitting device has properties such as self-light emission, high brightness, high efficiency, low driving voltage, a wide viewing angle, high contrast, a high speed responsiveness and the like.
In the organic light emitting device, the material that is used as the organic material layer may be classified into a light emitting material and an electric charge transporting material, for example, a hole injection material, a hole transporting material, an electron transporting material, an electron injection material, and the like, according to a function thereof. Further, the light emitting material may be classified into blue, green, and red light emitting materials and yellow and orange light emitting materials required for implementing better natural colors, according to the emission color. Meanwhile, when only one material is used as a light emitting material, due to interaction between molecules, there are problems in that the maximum light emitting wavelength moves to the long wavelength, the color purity is lowered, or efficiency of the device is lowered due to a reduced effect of light emission, and thus in order to increase light emission efficiency through increasing color purity and energy transfer, a host/dopant system may be used as the light emitting material.
In order to allow the organic light emitting device to sufficiently show the above-described excellent properties, a material constituting the organic material layer in the device, for example, a hole injection material, a hole transporting material, a light emitting material, an electron transporting material, an electron injection material and the like need to be supported by stable and efficient materials above anything else, but the development of a stable and efficient organic material layer material for organic light emitting device has not been sufficiently achieved. Therefore, there is a continuous need for developing a new material, and the necessity for developing the aforementioned material is similarly applied to the above-described other organic electronic devices.